Resolution of a Cystic Endodontic-Periodontal Lesion Utilizing Combined Apicoectomy and Guided Tissue Regeneration: A Case Report

INTRODUCTION: Endodontic-periodontal combined lesions pose a treatment challenge for clinicians, especially when the lesion is persistent and does not show signs of healing after initial endodontic treatment. This case report describes interdisciplinary management of a non-healing combined endodontic-periodontal lesion related to a peri-apical cyst, through a combined approach of apicoectomy and guided tissue regeneration (GTR) with enamel matrix derivative (EMD). Most documented cases have been treated in a sequential manner, with minimal literature present on the effects of a combined approach utilizing EMD for the treatment of these lesions. CASE PRESENTATION: A 72-year-old male patient presented with an endodontic-periodontal lesion at tooth #31 initially treated with nonsurgical root canal therapy. The lesion was not responsive to initial endodontic treatment. The patient was informed of questionable prognosis, however wished to save the tooth. Tooth #31 was treated via a combination approach of apicoectomy with bioceramic putty retrograde filling, followed by GTR of the defect using allograft, EMD, and resorbable barrier membrane. The lesion was biopsied and diagnosed as a periapical cyst. Clinical and radiographic examination at 1 year showed resolution of lesion, reduction in probing depths, and good bone fill of the defect. CONCLUSION: Traditionally, endodontic-periodontal lesions, which were not responsive to initial therapy, would be given a questionable prognosis and be extracted. This case demonstrates that non-healing, peri-apical lesions may be cystic in nature and effectively managed utilizing a combined approach, with apicoectomy and GTR with EMD, to produce a stable outcome.